The Cert Spotter alternative with a free hosted tier and flat pricing
Verified 19 Aug 2026
Cert Spotter, from SSLMate, is a well-regarded certificate monitor. Its open-source command-line tool watches the Certificate Transparency logs and alerts you when a certificate is issued for one of your domains, which is a quick way to catch a mis-issued or unexpected certificate. SSLMate also runs a hosted Cert Spotter service that adds a dashboard, deployment checks for a mismatched hostname or an incomplete chain, and faster, multi-location checks on its paid plans. It is a serious tool built by people who know Certificate Transparency deeply, and this page will not pretend otherwise.
Two things make CertPost a simpler fit when the job is the health of the certificate you serve.
Free and hosted. Cert Spotter's free path is the open-source tool you install and run yourself, and it watches Certificate Transparency logs. It alerts on a newly issued certificate, and it does not read the certificate your server actually serves. The hosted Cert Spotter service, which does check the served certificate, is paid only, with a 30-day trial and no permanent free tier, priced in tiers by how many endpoints you monitor. CertPost is hosted from the first check: three certificates are free forever, no card, and each one is read from a real TLS handshake for expiry, the full chain including intermediates, and hostname and SAN match, with Certificate Transparency alerts included.
Scope and price. Above the free tier CertPost is a flat $29/month for unlimited certificates, rather than a plan that steps up with your endpoint count. Around the certificate it also watches domain-registration expiry, which is a separate clock from the certificate, and DNS drift, and it reads the certificate on any TLS port, mail and admin ports included, over IPv4 and IPv6.
If Certificate Transparency monitoring is the specific job, Cert Spotter does it well, and the open-source tool is free to run. If you want a hosted tool that reads the served certificate's health, includes Certificate Transparency alerts, and adds the domain and DNS around it at a flat price, CertPost covers more of it in one place.
Trying CertPost next to Cert Spotter:
1. Sign up free and paste the certificates you care about most.
2. Add the parts a Certificate Transparency feed does not cover: the served certificate's expiry and chain, the mail and admin ports, and the apex domain for registration expiry.
3. Keep Cert Spotter for Certificate Transparency issuance alerts if you rely on them, and send both to the same inbox or team channel so an issuance alert and a chain break land in one place.
Import your domain list in 2 minutes — 3 certificates free, no card.
Start free